KBC first aired in 2000 and was hosted by Amitabh Bachchan, his first appearance on Indian television. KBC initially offered contestants the chance to win up to ten million Rupees, but doubled this in 2001 to two crore Rupees, further adjusted from the fourth season to include a jackpot of 50 million rupees. The season ended in 2001. The show was well received from the very first season.[1]

On 5 August 2005, the show was restarted after a four-year hiatus, and renamed Kaun Banega Crorepati Dwitiya (Kaun Banega Crorepati the Second, or KBC 2) in which the final prize amount was doubled to 20 million rupees. It was abruptly ended by STAR Plus after the host Amitabh Bachchan fell ill in 2006.[2] Mr Bachchan had shot 61 of the 85 episodes when he fell ill. He announced he would return after he recovered, but when his health prevented him filming the remaining 24 episodes, Star TV took the decision to axe it.

Star Television recruited Shahrukh Khan to host the third season of the show. Khan was at peak of his career and was considered an ideal replacement for Amitabh Bachchan. The grand prize remained 20 million Rupees (approx. US$430,000). The third season of the show began airing on 22 January 2007. The season ended on 19 April 2007 with a special finale. The key sponsors of the third season were AirTel, Unit Trust of India (UTI Mutual Funds) and ITC Limited.

The fourth season (called KBC4) was hosted by Amitabh Bachchan and started on 11 October 2010, on Bachchan's 68th birthday. This season was telecast 4 days a week on every Monday - Thursday at 9 PM IST. The tagline of this season used for was Koi Bhi Insaan Chota Nahi Hota (English: No Human is Small). The show moved from Star Plus to Sony Television (the programme is produced by Sony Pictures Television, which owns the format, but Siddhartha Basu remained the director and creative head. The new logo designed for the fourth season incorporated the new Indian Rupee symbol, which was unveiled the same year. The phone lines for the fourth season opened on 2 August 2010 at 9 PM IST.[3] According to online news sources, over five million (5 million) people participated in KBC 4 auditions.[citation needed] The total prize money was increased to 50 million, and a jackpot question for 50 million (approx. USD 1 million) was added. The fourth season of the show was highly successful due to the return of former host Amitabh Bachhan.[4] The season ended on 9 December 2010.

Like many other versions of the show, the season 4 reduced the number of questions from 15, to 13 in this version.[5]

The Indian version adopted the clock format from the US version and is the fourth country's version to do (the others being Japan and the UK; although the US version abandoned the clock for the 2010–11 season when the show's 2010 format changes were made), although the time limits were shorter than in the UK version. There was a 30 second time limit for questions 1 and 2, and a 45 second time limit for questions 3 to 7, but questions 8 to 13 were not timed.[6][7]

The clock stops whenever a lifeline is used, and if the contestant allows the clock to run out, he/she will be forced to walk away. There were four lifelines: Audience Poll and Phone a Friend will make a return, along with the addition of two new lifelines Ask the Expert and Double Dip.

Amitabh Bachchan also hosted the fifth season of KBC in 2011. The fifth season started on 15 August 2011 on the Independence Day of India with the same format and ended on 17 November 2011. It was aired 4 days a week same as the 4th season at 8:30 PM IST for 1 and a half-hour. The tagline used for the season was Koi Bhi Sawaal Chota Nahi Hota(English: No Question is Small) (Literary means: Every Question is Important). This season was the most popular show on Indian television in 2011.[8] The show became a massive hit with audiences and broke many TRP Records. CNN IBN awarded Indian of the Year- Entertainment to Team KBC and Amitabh Bachan. The show also grabbed all the major Awards for its category and was a massive hit.

There were 13 questions same as in season 4. There was "Manchaha Padav" in the money tree and 'Mrs. Tick Ticki' replaced 'Ghadiyal Babu'. The "Ghar Baithe Jeeto Jackpot" competition allowed viewers to send an answer to a question via SMS during the show, with 100,000 Rupees going to the randomly picked winner, who can double or triple this amount by correctly answering further questions.

This sixth season (called KBC 6) was also hosted by Amitabh Bachchan and was commenced on 7 September 2012. However the news making all the headlines was his pay package at a staggering 135 million per episode making him the highest paid TV artist of all time. It aired every Friday to Sunday at 8:30 PM IST on Sony TV. The season got over on 26 January 2013. The tagline used for the season was Sirf Gyaan Hi Aapko Aapka Haq Dilata Hai (English: Just the knowledge that draws your right as you). There were 13 questions same as in season 4 and 5. The show opened with the tremendous response with the first episode fetching 6.7 TRP and broke all the previous records on the channel.[9] It was aired in Pakistan on Express Entertainment.

Also, in this season, the team of KBC started a new tradition of special appearance of socially backward people titled as "Dusra Mauka". Sonali Mukherjee, a victim of acid throwing, appeared along Lara Dutta. On 13 January 2013 another segment of this show was aired in which, Manoj Kumar, a Mahadalit (poorest of the poor class) was accompanied by famous Indian actor Manoj Bajpayee.

The rehearsals for the show begun on 26 June 2013.[10] Registration started from 9:00 PM on 27 June 2013.

This seventh season (called KBC 7) was also hosted by Amitabh Bachchan. The telecast time of this season was same as the season 6. 'Seekhna Bandh Toh Jeetna Bandh' (English: Learning stops so Winning stops) (Literary means: Learn to Win) was used as the tagline for this season. The total prize money was increased to 70 million, and the no. of questions increased from 13 to 15. The season was commenced on 6 September 2013, exactly after a year of KBC 6, and ended on 1 December 2013. Due to the huge jackpot of Rs. 70 million, the season was also referred to as Kaun Banega MahaCrorepati (English: Who Wants to be a Multi-Millionaire).

The season had a few changes, including a new lifeline called Power Paplu. This lifeline aided those who seek to revive any already used lifeline. There were total 15 questions to reach jackpot question. However, Double Dip and Ask The Expert were discontinued and in lieu 50:50 and Flip The Question were revived. The prize for jackpot question was increased from 50 million to 70 million. The "Kaun Banega Crorepati 2013" set was a 360-degree multimedia stage, making India the first ever country to change the "Who Wants To Be A Millionaire" set worldwide. Like all the seasons there was a Ghar Baithe Jeeto Jackpot question. There were four questions in the new feature 'Sapta Koti Sandook (English: The Seventh Jackpot)' that let contestants win from 10 million, 30 million, 50 million and finally 70 million. The system of Fastest Finger First was also altered, where the winner of leader board formed at the end of 3 questions, sits on the Hot Seat.

This season got its first crorepati Taj Mohammed Rangrez. He is a history teacher from Udaipur, Rajasthan and was the first contestant to walk away with the title of "Crorepati" this season. He won Rs. 10,000,000 ( Rs. ten million).Afterwards he said that he didn't use the Flip The Question lifeline by which a question can be changed and a new question will appear because he wanted money for the operation of his child. If he would have used the life line he wouldn't know whether he would be able to give the correct answer and after using the lifeline he will not be able to quit the show which meant that if he gave wrong answer he may only win Rs. 320,000 and he would not be able to give money for the operation of his child.

The registrations of Kaun Banega Crorepati 8 were commenced on 22 July 2014 and the shooting started on 2 August 2014.[11] Shooting of the entire show was held in Surat. This was the first time that KBC was shot outside Mumbai.[12]

The grand premiere episode of the series was aired on 17 August (Sunday) at 8:30 PM IST for 3 hours. The season aired regularly from 17 August on every Monday - Thursday at 8:30 PM for 1.5 hours. After couple of weeks, the series aired only for an hour. The season ended on 6 November 2014, and aired its two grand finale episodes on 9 November (Sunday) at 8:30 PM IST for 1.5 hours and on 16 November 2014 (Sunday) at 7:30 PM for 2.5 hours. The tagline for the season was 'Yahan Sirf Paise Nahi, Dil Bhi Jeete Jate Hain'. Three special guests appeared in the grand premiere episode. Television comedian, Kapil Sharma from Colors TV's television series Comedy Nights with Kapil was the first guest of the show. Moreover, iconic cops Dayanand Shetty (Daya) and Aditya Shrivastava (Abhijeet) from Sony TV's television series CID were also seen. Then the valiant warrior and Rajput hero, Maharana Pratap a.k.a. Faisal Khan from Sony TV's television series Bharat Ka Veer Putra – Maharana Pratap left the audience spellbound with a stellar dance performance.[13] Among others Shillong Chamber Choir led by Neil Nongkynrih performed a medley of evergreen songs of Bollywood followed by a patriotic song at the opening ceremony of KBC-8.[14] Murtuza Hashmi was the 1000th contestant on 8 September 2014.[15] Sarthak and Achin Narula were the first contestants to win Rs. 7 Crores on the show (and the highest Asian top prize winner so far). Megha Patil (Vasai) was the first female crorepati winner in KBC 8 on 20 October 2014.

The standard Millionaire format is used, with the Fastest Finger contest before the main game.

All contestants must be over the age of 18 and citizens of India to be eligible. The person must not be a former "Kaun Banega Crorepati" contestant and, as defined in the Income Tax Act, 1961, must also be a resident of India. Furthermore, they may not be employees of the production company, broadcaster, or prize providers.

The contestant is asked to pick a "Padao", which means that after a certain question, for example after Question 6, he will at least get that amount of money after answering that question rightly. The pre-2010 United States format of a "shot clock" will be used in the first few questions—45 seconds. After the Padao, there is no time limit. Actually "padao" is the Hindi word which means to decide the specific level of rest. Essentially a milestone--"parachute" question. Once the question is answered right that money is considered "safe" and will win that amount if he fails any of the questions after the Padao Question.

The money won after each question is roughly doubled from the previous amount won, exponentially increasing the amount won after each correct answer until the contestant reaches the final question, after which they win the maximum prize.

A contestant can use a lifeline when he/she is undecided about which answer is correct. The following table shows different lifelines used in different seasons.

Life lines in Different seasons

Life line

Audience Poll

Fifty-Fity

Phone a Friend

Flip

Power paplu

Tri-guni

Double Dip

Ask an Expert

Season 1

Y

Y

Y

N

N

N

N

N

Season 2

Y

Y

Y

Y

N

N

N

N

Season 3

Y

Y

Y

Y

N

N

N

N

Season 4

Y

N

Y

N

N

N

Y

Y

Season 5

Y

N

Y

N

N

N

Y

Y

Season 6

Y

N

Y

N

N

N

Y

Y

Season 7

Y

Y

Y

Y

Y

N

N

N

Season 8

Y

N

Y

N

N

Y

Y

N

Audience Poll: If the contestant uses this lifeline, it will result in the host repeating the question to the audience. The studio audience get 10 seconds to answer the question. Audience members use touch pads to designate what they believe the correct answer to be. After the audience have chosen their choices, the results are displayed to the contestant in percentages in bar-graph format and also shown on the monitors screens of the host and contestant, as well as the TV viewers.

Fifty-Fifty (50/50): If the contestant uses this lifeline, the host will ask the computer to randomly remove and eliminate two of the "wrong" answers. This will leave one right answer and one wrong answer, resulting in a situation of eliminating 50% of the choices as well as having a 50% chance of getting the answer right if the contestant is in a situation of making a guess. In 2010, 50/50 was replaced by Double Dip but it again replaced Double Dip in 2013.

Phone a Friend: If the contestant uses this lifeline, the contestant is allowed to call one of the three pre-arranged friends, who all have to provide their phone numbers in advance. The host usually starts off by talking to the contestant's friend and introduces him/her to the viewers. After the introduction, the host hands the phone call over to the contestant who then immediately has 30 seconds to ask and hope for a reply from their friend.

Flip the Question: The contestant earned this lifeline upon answering the fifth question. The computer replaced, at the contestant's request, one question with another of the same monetary value. Any lifelines used on the original question prior to the switching were not reinstated.

Power Paplu: This lifeline will aid those who seek to revive any already used lifeline. It can be used even after using one lifeline, out of 4 lifelines. It is used only once.[16]

Tri-guni: This lifeline gives the contestant an opportunity to ask for the answer from three genius people which keeps on changing in every episode of KBC.[17]

Double Dip: This lifeline allows the contestant to make two guesses at a question. Getting both answers incorrect results in the contestant's winnings dropping back down to the last milestone achieved. This lifeline differs from others in that once the player has chosen to use this lifeline, he/she must answer the question, and cannot walk away or use any further lifelines on that question. In the 4th season this lifeline was made available after the contestant correctly answers the seventh question. In the 5th season, however, all 4 lifelines were made available from the start of the game.

Expert Advice: This lifeline allows the contestant to ask an expert via live face-to-face audio and video connection. The expert could be anyone from a celebrity to a previous Millionaire contestant. Expert Advice is available throughout the game. There is no set time limit, and the contestant and expert are allowed to discuss the question.

Since its launch in the year 2000, KBC has inspired thousands with Amitabh's catchy phrases like "Lock kiya jaye?" which has been used in the media a countless number of times, an example being in the 2001 film Nayak: The Real Hero starring Anil Kapoor and Rani Mukerji. Other phrases from the show, as said by Amitabh Bachchan also fetched cult following: "Deviyon aur Sajjano", "Samay samapti ki ghoshna" etc. With the third season that was hosted by Shahrukh Khan, wordage such as "Lock kiya jaye?" were changed to "Freeze it!". Additional expressions were introduced in KBC3 like "Kuch sawaal aapki zindagi badal sakte hain!" which is the official motto of the third season and "Kachcha Kachcha? Pakka Pakka?" that figuratively means "Are you sure or are you not sure?". "Tez Teekha Tabadtor" as well as "Koi Sawaal Chota Nahi Hota" in the fourth season of the show became immensely popular. "Koi Sawaal Chota Nahi Hota" was replaced by "Koi Insaan Chota Nahi Hota" in the fifth season of the show. In the same season new phrase "Panchkoti Mahamani" was used,which was replaced by "Panchkoti Gyankumbh" in the following season. In the sixth season, the motto was changed to "Sirf gyaan hi aapko aapka haq dilata hai". In the seventh season motto was "Sapta Koti Maha Money" & new phrase, "Seekhna Band Toh Jeetna Band". In the eighth and current season, motto "Yahan Sirf Paise Nahi, Dil Bhi Jeete Jate Hain" has been used.

The show plays a major role in the movie Slumdog Millionaire, with Anil Kapoor playing Prem Kumar, the game show host, though Shah Rukh Khan was asked to play. The movie is an adaptation of the Vikas Swarup novel Q & A (although the novel depicted a fictional quiz show called Who Will Win a Billion?), and is also loosely connected to a real-life cheating incident on the UK version of the show titled "Who wants to be a millionaire?".